THIS invention relates to printable compositions for use in electronic and electrical applications in general, and specifically in those applications where semiconducting properties are required.
Semiconductor nanoparticles, with a characteristic size of a few nanometers up to several hundred nanometers, are a widely studied type of material, in which size effects dominate over properties of the bulk material. In general, depending on the specific material and its application, three different size-related phenomena may change the electronic, optical, thermal and mechanical properties of such nanoparticles:                1. a different structure and composition compared to the known bulk phases;        2. the higher surface to volume ratio of the particles compared to the bulk phase, which causes surface states and processes to dominate; and        3. quantum confinement effects when the size of the object is similar to or smaller than the wavelength and coherence length of a fundamental excitation (electronic state, optical wavelength or phonon excitation).        
Various semiconductor inks using such particles have been disclosed. For example, organic semiconducting inks comprising semiconducting particles dispersed randomly in a matrix or binder, and inorganic semiconducting inks in which the semiconducting particles form an interconnecting structure, are known.
In such applications, the binder or matrix material is often a polymer which is soluble in an easily obtainable solvent, such as acetone, chloroform or toluene. Common examples are polystyrene and cellulose acetate butyrate (CAB), which are insulators, and polythiophenes which are conjugated hole conductors, allowing charge transport between isolated particles.
It is an object of the invention to provide alternative printable compositions comprising semiconductor particles.